BUT I DEFEATED PSYCHO MANTIS!!!!!! and without plugging my controller to the second plug. No, you don't have to stay near the statues. First thing useful I did, was to destroy the pictures of the chinese person in the wall. Then all things that Psycho Mantis throw at you. The hard thing was the armor. Anyway, my always trusty strategy for bosses, that let you think and evade their attacks is: running in circles by the walls. Yea, you run next to the walls in circles, that lets you think in what to do, searh weaknesses of the Boss, and more useful stuff. Maybe that sounds like if I were a little child, but it works! XD really.
Cool thing when I encountered Psycho Mantis was, that when I aimed him in the head for a "critical hit" or to do more damage using the 1st person vision, if you take too long, the screen turns gray and black, and blurry, then you had to get out of 1st person vision and battle him in 3rd person one, and if you wanted, again the 3rd person one. Sometimes, Psycho Mantis block your screen showing gray and black and in a corner "(X number) Video" yea it was like "3 Video" or change the numbers. That was cool, so cool. But it was kinda easy to defeat him, I only lost twice against him! XD am I good or am I good? XD
LOOK AT ME!!!!! Good! now... leave me alone! XD

Go for it, kid!